//工具类
var subs=function(str){
	//去除单位 eg: subs('200px') ==>200
	if(!str.length){
		throw new Error('不能传入空字符');
		return;
	};
	return str.substring(0,str.length-2) | 0;
}
var rand=function(min,max){
	return Math.random()*(max-min)+min | 0;
}
var colors=['#e928b5','#f51020','#c7f510','#f56110','#e928b5','#f51020'];
